I’m wondering how to change the default for the lightbox image to show the original size or large version rather than one of the custom sizes. The custom sizes seem to always crop the image and I want to automatically display the whole thing. I’d also like to know how to change the porfolio preview image so that it wasn’t, by default, a cropped version of the image.

The images need to be cropped by default ( for example: if you had an image 5000px by 5000px you wouldn’t be able to see it all).

You can adjust the size it’s cropped to by changing the values of width and height in functions.php or create a new entry called XXL and change the width and height to the maximum size you’ll need to display.

Please note: if you change the sizes of images in functions.php, only images uploaded after that point will use the new values, any existing images will need re-uploading to be resized by WordPress.